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The present invention is a surface controlled subsurface safety valve (SCSSV) for use in a well, preferably a hydrocarbon producing well. Many hydrocarbon producing wells contain a subsurface safety valve located down hole in the production string to shut off hydrocarbon flow in the event of an emergency. Well production strings continue to increase in depth, particularly for offshore wells, due to increases in both well and water depths. In order to prevent injury to personnel and to protect the environment and equipment, the present invention addresses the need for a subsurface safety valve that closes quickly and reliably when installed at any depth, and especially these increased depths, within a well.
The present invention is a surface controlled subsurface safety valve (SCSSV) for use in a well, preferably a hydrocarbon producing well. The SCSSV comprises a valve body having a longitudinal bore for fluid to flow through, a bore closure assembly, a pressure balanced drive assembly, and a fail safe assembly. The bore closure assembly is positioned and normally biased to close the bore to fluid flow. The drive assembly is coupled to the bore closure assembly for driving the bore closure assembly to an open position. The fail safe assembly is positioned and configured to hold the bore closure assembly in the open position in response to a hold signal and to release the valve to return to the safe, closed position upon interruption of the hold signal.